When Bigger Is Not Greener: Ensuring the Sustainability of Power-to-Gas Hydrogen on a National Scale.

As the prices of photovoltaics and wind turbines continue to decrease, more renewable electricity-generating capacity is installed globally. While this is considered an integral part of a sustainable energy future by many nations, it also poses a significant strain on current electricity grids due to the inherent output variability of renewable electricity. This work addresses the challenge of renewable electricity surplus (RES) utilization with target-scaling of centralized power-to-gas (PtG) hydrogen production. Using the Republic of Korea as a case study, due to its ambitious plan of 2030 green hydrogen production capacity of 0.97 million tons year-1, we combine predictions of future, season-averaged RES with a detailed conceptual process simulation for green H2 production via polymer electrolyte membrane (PEM) electrolysis combined with a desalination plant in six distinct scale cases (0.5-8.5 GW). It is demonstrated that at scales of 0.5 to 1.75 GW the RES is optimally utilized, and PtG hydrogen can therefore outperform conventional hydrogen production both environmentally (650-2210 Mton CO2 not emitted per year) and economically (16-30% levelized cost reduction). Beyond these scales, the PtG benefits sharply drop, and thus it is answered how much of the planned green hydrogen target can realistically be "green" if produced domestically on an industrial scale.

Proposing a new solution for marine debris by utilizing on-board low-temperature eco-friendly pulverization system.

Developing an effective and efficient recycling process for marine debris (MD) is one of the most urgent issues to maintain environmental sustainability on Earth. However, restricted storage capacities and secondary pollution (e.g., microbial adhesion, putrefaction) limit the proper MD recycling. Here, we proposed a complete eco-friendly low-temperature MD pulverizing system that utilizes excessive liquefied natural gas (LNG) cold energy (LCE) in an LNG propulsion ship to improve the efficiency and effectiveness of MD recycling. The prototype design of the low-temperature pulverization (LTP) system showed that consumable refrigerant (liquid nitrogen) up to 2831 kg per hour could be substituted. Furthermore, with a 20% ship output, 1250 kg of MD could be treated with 363 kg of additional refrigerant. In addition, LTP systems utilizing LCE could increase the storage capacity by more than 10 times compared to bulk MD while minimizing the required energy consumption. To determine the feasibility of LTP for MD recycling, four types of plastics obtained from actual MD from a coastal area in Busan, Korea were classified and tested.

Synthesis of Macro-Porous De-NOx Catalysts for Poly-Tetra-Fluoro-Ethylene Membrane Bag Filter.

This study examined the effects of the porosity of catalytic bag-filter materials for applications to the SNCR (selective noncatalytic reduction)-SCR (selective catalytic reduction) hybrid process for highly treating nitrogen Oxides (NOx) in the exhaust gas of a combustion process. A V2O5/TiO2 catalyst was dispersed in a PTFE (poly-tetra-fluoro-ethylene) used as the catalytic bag-filter material to remove particulate matter and nitrogen oxides contained in the combustion exhaust gas. Macroporous alumina was added into a V2O5/TiO2-dispersed PTFE to improve the catalytic activity of V2O5/TiO2 dispersed in the PTFE material. In this study, the textural properties and denitrification performances of the V2O5/TiO2-dispersed PTFE materials were examined according to the addition of macro-porous alumina. When the denitrification catalyst was solely dispersed in the PTFE material, the catalyst inside the PTFE backbone had low gas-solid contact efficiency owing to the low porosity of the PTFE materials, resulting in low denitrification efficiency. On the other hand, the catalytic activity of V2O5/TiO2 dispersed inside the macro-porous PTFE material was significantly enhanced by adding macro-porous alumina into the PTFE matrix. The enhanced textural properties of the macro-porous PTFE material where V2O5/TiO2 was uniformly dispersed proved the facilitated diffusion of combustion exhaust gas into the PTFE material.

Spontaneous and applied potential driven indium recovery on carbon electrode and crystallization using a bioelectrochemical system.

Indium removal and recovery on a carbon electrode under a microbial fuel cell (MFC)-based oxidation/reduction reaction were examined using synthetic wastewater. More than 90% of In3+ ions were removed after continuous operation of the MFC for 14 days with an average current generation of ∼50 µA. During operation, indium particulates formed on the cathode carbon electrode. Scanning electron microscopy equipped with X-ray energy dispersive spectroscopy showed that they were composed of amorphous and crystalline indium hydroxides (In(OH)3 and In(OH)·H2O). When the current flow was reversed to drive the oxidation of the particles to recover the indium from indium hydroxides, a few indium oxide (In2O3) nanocrystals with a rectangular platelet shape formed on the electrode, while the majority of the amorphous and crystalline indium hydroxides re-dissolved into the aqueous environment. Overall, these results demonstrate a feasible route towards the MFC-based recovery of indium with the simultaneous generation of bioelectricity.

Epidemiology of Type 1 Diabetes Mellitus in Korea through an Investigation of the National Registration Project of Type 1 Diabetes for the Reimbursement of Glucometer Strips with Additional Analyses Using Claims Data.

BACKGROUND: The aim of this study was to estimate the prevalence and incidence of type 1 diabetes mellitus (T1DM) in Korea. In addition, we planned to do a performance analysis of the Registration Project of Type 1 diabetes for the reimbursement of consumable materials. METHODS: To obtain nationwide data on the incidence and prevalence of T1DM, we extracted claims data from July 2011 to August 2013 from the Registration Project of Type 1 diabetes on the reimbursement of consumable materials in the National Health Insurance (NHI) Database. For a more detailed analysis of the T1DM population in Korea, stratification by gender, age, and area was performed, and prevalence and incidence were calculated. RESULTS: Of the 8,256 subjects enrolled over the 26 months, the male to female ratio was 1 to 1.12, the median age was 37.1 years, and an average of 136 new T1DM patients were registered to the T1DM registry each month, resulting in 1,632 newly diagnosed T1DM patients each year. We found that the incidence rate of new T1DM cases was 3.28 per 100,000 people. The average proportion of T1DM patients compared with each region's population was 0.0125%. The total number of insurance subscribers under the universal compulsory NHI in Korea was 49,662,097, and the total number of diabetes patients, excluding duplication, was 3,762,332. CONCLUSION: The prevalence of T1DM over the course of the study was approximately 0.017% to 0.021% of the entire population of Korea, and the annual incidence of T1DM was 3.28:100,000 overall and 3.25:100,000 for Koreans under 20 years old.